I need convert a VCL component from 32bit to 64bit (Delphi XE2). Now infact I can install it only if I select "32bit Platform", if I select "64bit Platform" I can compile it but not install (there is not the install menu). How can I add 64bit support and install it for 64bit application?
If you mean "install it into the IDE", the simple answer is that you cannot.
The IDE is a 32-bit application and is not designed to host 64-bit DLL's. Any components or plug-ins must be compiled for 32-bit in order to work with the IDE itself.
64-bit support in a component is for runtime support only, not design-time.
来源：https://stackoverflow.com/questions/7719297/how-add-delphi-xe2-64bit-support-to-a-simple-delphi-xe2-32bit-vcl-component